I might not remember correctly but
lxc came out around 2008.
Docker in 2013. The lxc
commands had the trend of dashes in their name — lxc-attach, lxc-snapshot,
lxc-copy and so forth. It had lots of boilerplate and a steep learning curve.
Then lxd arrived (in 2015?)
to make everything user friendly. lxd is preferred. I still mostly use lxc
out of habit.